1. Field of the Invention
The present invention relates to a technique of simultaneously displaying a plurality of cross sectional images of three-dimensional medical image data.
2. Description of the Related Art
Three-dimensional medical image data can be made into groups of cross sectional images respectively in the three orientations of cross sections called an axial cross section (cross section dividing the trunk at any height), a coronal cross section (cross section dividing the trunk into anterior and posterior halves), and a sagittal cross section (cross section dividing the trunk into right and left halves). Each group of cross sectional images consists of a plurality of cross sectional images put in each of the three orientations of cross sections. Conventional techniques are capable of simultaneously displaying the three cross sectional images by selecting an image from each group of cross sectional images and displaying the selected images in respective image display areas allocated for these images.
As a general method of making diagnoses on images by using a conventional image display apparatus, a medical doctor first scrolls the axial cross sectional image looking for an abnormal shadow (candidate). The term “scroll” here refers to a display controlling method of sequentially switching the cross sectional images to display according to a user's instruction. That is a method of displaying the cross sectional images by serially switching the images to display, where, provided that the cross sectional images included in a single group of cross sectional images are denoted by I1 to Im and the cross sectional image to display is denoted by Ii (i={1−m}), the index value i is incremented or decremented by a predetermined number (usually, one) for switching the images.
When the doctor finds one or more abnormal shadows (candidates) during the above described scrolling of the axial cross sectional image, the doctor scrolls the cross sectional images close to those showing the abnormal shadows (candidates) again to minutely observes the shadows (candidates). If the doctor feels awkward in determining the three-dimensional distribution of abnormal shadows (candidates) from only one group of cross sectional images, the doctor displays the three cross sectional images (axial cross section, coronal cross section, sagittal cross section)
Japanese Patent Application Laid-Open No. 2004-173910A discloses an approach of switching display for a single group of cross sectional images (in the embodiment, a group of axial cross sectional images). Japanese Patent Application Laid-Open No. 2004-173910A describes that the invention can improve medical diagnoses in efficiency and accuracy by providing selective display of cross sectional images which show the abnormal shadow candidates detected by the image display apparatus for the doctor who is making a diagnosis by observing the single group of cross sectional images.
Each of these conventional techniques of displaying three cross sectional images has image display areas respectively for the three cross sectional images. With these techniques, a user can scroll the cross sectional images only in a specified display area by specifying a single display area among three display areas.